CVE-2024-49850 is a vulnerability identified in the Linux kernel's handling of BPF (Berkeley Packet Filter) core relocation records, specifically those of the type BPF_CORE_TYPE_ID_LOCAL. The issue arises when the kernel processes malformed relocation records referencing non-existent BTF (BPF Type Format) types. In such cases, the function bpf_core_calc_relo_insn attempts to dereference a null pointer, leading to a kernel null pointer dereference. This can cause a denial of service (DoS) by crashing the kernel or potentially triggering undefined behavior. The vulnerability stems from insufficient validation of user-supplied relocation records before processing, allowing malformed inputs to propagate into kernel space. The simplest reproducer involves a minimal BPF program with a relocation record that references a non-existent type ID, which triggers the null pointer dereference. The fix involves adding proper validation checks higher in the call stack to prevent malformed relocation records from reaching vulnerable code paths. This vulnerability affects Linux kernel versions containing the specified commit hashes prior to the patch. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. However, the vulnerability impacts a fundamental kernel subsystem used widely for packet filtering, tracing, and security enforcement, making it a significant concern for systems running vulnerable Linux kernels.

For European organizations, the impact of CVE-2024-49850 primarily involves potential denial of service conditions on Linux-based systems that utilize BPF functionality. Many enterprise servers, cloud infrastructure, networking equipment, and container platforms in Europe run Linux kernels that include BPF support. A successful exploitation could cause kernel crashes, leading to system downtime, disruption of critical services, and potential cascading failures in dependent applications. While this vulnerability does not directly enable privilege escalation or arbitrary code execution, the resulting instability could be leveraged by attackers to degrade service availability or as part of a multi-stage attack. Organizations relying on Linux for network monitoring, security enforcement, or performance tracing should be particularly vigilant. Additionally, sectors with high availability requirements such as finance, telecommunications, healthcare, and government services in Europe could face operational risks if vulnerable systems are exploited. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure.

European organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2024-49850 as soon as vendor updates are available. Specifically, they should: 1) Identify all systems running affected Linux kernel versions, especially those using BPF features extensively. 2) Apply vendor-provided kernel patches or upgrade to the latest stable kernel releases that address this vulnerability. 3) In environments where immediate patching is not feasible, consider disabling or restricting BPF usage through kernel configuration or security policies to reduce attack surface. 4) Monitor system logs and kernel crash reports for signs of null pointer dereferences or unexpected kernel panics related to BPF operations. 5) Employ runtime security tools that can detect anomalous BPF program loading or malformed relocation records. 6) Incorporate this vulnerability into incident response and vulnerability management workflows to ensure timely detection and remediation. 7) For containerized or virtualized environments, ensure host kernels are patched, as containerized workloads rely on host kernel security.